The goals of this study were (1) to evaluate the impacts of pesticides used for mosquito control on drinking water and (2) to investigate the removal of permethrin from water using activated carbon. A review of current literature on pesticide usage, toxicity, occurrence in the environment, and treatment techniques to remove pesticides from drinking water was conducted. The focus of the literature review was on pesticides used for mosquito control. Permethrin is a synthetic pyrethroid insecticide used extensively in the United States (US) for mosquito control and in agriculture, with approximately 2 million pounds applied each year. Permethrin was selected for investigation based on its widespread use in the US, its inclusion on the Contaminant Candidate List 3 (CCL3), its health hazards, and the lack of previous research on the removal of permethrin from drinking water. The removal of permethrin from water using powdered activated carbon (PAC) was investigated. Equilibrium adsorption experiments to assess removal of cis-, trans-, and total permethrin were conducted using two types of PAC (WPH 650 and WPH 1000). Initial total permethrin concentrations ranged from 2.0 to 4.6 ug/L. PAC doses ranged from 0.0 to 10 mg/L. Results showed that PAC addition is an effective method for removing permethrin from water. Total permethrin concentrations were reduced by 38% with 0.05 mg/L of PAC WPH 650, and reduced to below the detection limit with 3 mg/L of PAC WPH 650. Total permethrin concentrations were reduced by 35% with 0.05 mg/L of PAC WPH 1000 and by 83% with 5 mg/L of PAC WPH 1000. Results for cis- and trans- permethrin were similar. The Freundlich isotherm model provided appropriate fits to the data with an R-squared value of 0.91 for both WPH 650 and WPH 1000.